KR20190081832A - power management integrated circuit, OLED display device using the PMIC and operation method thereof - Google Patents

Abstract

The present invention relates to an electricity control integrated circuit, an organic light emitting display apparatus using the same and an operating method thereof. The electricity control integrated circuit is operated in an FCCM method only at a section in which a current is applied to display pixels and operated in a DCM (or PSM) method at a section in which a current is not applied to pixels, thereby maintaining image quality and reducing power consumption. To this end, the electricity control integrated circuit is configured by comprising: an integrated circuit driving power input end which receives driving power; an operational signal input end which receives a driving start enable signal; a driving voltage output end which outputs a voltage required for the operation of an organic light emitting diode provided at a panel of a display panel unit; a control signal input end which receives a control signal provided by a timing controller; and a power control unit which controls the driving voltage output end to be operated in a forced continuous conduction mode (FCCM) at a section in which pixels of a display panel have to be lit, and operated in a forced pulse skip mode (FPSM) at a section in which pixels thereof are not lit, corresponding to the control signal inputted through the control signal input end. Consequently, power consumption can be reduced while maintaining the image quality of the display and preventing the display panel unit from being damaged due to an error occurring in the electricity control integrated circuit.

Description

TECHNICAL FIELD [0001] The present invention relates to a power control integrated circuit, an OLED display device using the same, and a power management integrated circuit (OLED)

The present invention relates to a power control integrated circuit and an OLED display using the same and a driving method thereof. More particularly, the present invention relates to a power control integrated circuit The present invention relates to a power control integrated circuit capable of protecting a panel by automatically switching to a PSM (FPSM) mode, which is a specific low frequency switching mode, and an OLED display using the same and a driving method thereof.

A power management integrated circuit (PMIC) for a general display device operates differently depending on the output current. That is, as shown in Figure 1, the power control integrated circuit threshold (i _th) output current on the basis of (i) the threshold value (i _th) is less than the size, the discontinuous current mode (Discontinuous Conduction Mode of: DCM (Pulse-Skipping Mode) or Pulse-Skipping Mode (PSM). When the threshold value _(th i) based on the output current (i) is greater than the size of the threshold value (i _th) PMIC the CCM: operates in (Continuous Conduction Mode CCM) method.

The PMIC according to the related art drives a display device of a portable terminal by applying a Forced Continuous Current Mode (FCCM).

Therefore, although the image quality can always be maintained at high quality, the CCM system always operates, and the power consumption consumed by the power source unit is increased.

In addition, when a problem occurs in the power control integrated circuit that supplies power to the display panel unit, if the current continues to flow to the display panel unit, the brightness of the display panel may increase by five times or more. When such an organic light emitting display device is applied to a head mount display, there is a risk that the user may be blinded due to excessive brightness.

An object of the present invention is to provide a power control integrated circuit capable of reducing power consumption while maintaining the quality of image quality, and an organic light emitting display using the same and a method of driving the same.

Another object of the present invention is to prevent a panel from being burned when a switch circuit of an internal circuit of a power control integrated circuit operates in an abnormal state and a short circuit occurs and the display panel is damaged. And an organic light emitting display device using the same, and a driving method thereof.

It is another object of the present invention to provide a power control integrated circuit capable of preventing a problem caused by an error state of a power control integrated circuit internal circuit, an organic light emitting display using the same, and a driving method thereof.

It is still another object of the present invention to provide a power control integrated circuit capable of preventing a display panel from being damaged by interrupting power supplied to a display panel when an error occurs in a power control integrated circuit, And to provide a driving method.

According to an aspect of the present invention, there is provided a power control integrated circuit including an integrated circuit driving power input terminal receiving driving power; An operation signal input terminal for receiving a drive start enable signal; A driving voltage output terminal for outputting a voltage required for operation of the organic light emitting diode provided in the panel of the display panel unit; A control signal input terminal receiving a control signal provided from a timing controller; And a FCCM (Forced Continuous Conduction Mode) method is operated in a period in which a pixel of the display panel is to be turned on according to a control signal input through the control signal input terminal. In a period in which pixels are not lit, a specific low- And a power controller for controlling the driving voltage output terminal to operate in a Forced Pulse Skip Mode.

The driving voltage output terminal of the power control integrated circuit according to the present invention includes a pair of driving voltage switches SWD1 and SWD2 connected to the VDD voltage input terminal of the display panel unit; And a pair of discharge voltage switches SWS1 and SWS2 connected to the VSS voltage input terminal of the display panel unit.

The power control unit of the power control integrated circuit according to the present invention checks whether the voltage supplied to the display panel unit through the driving voltage output terminal is equal to or lower than a preset threshold voltage, Cut off the power supply to the part.

An OLED display according to an exemplary embodiment of the present invention includes a display panel unit including a display panel, a gate driver, and a data driver; A timing controller for analyzing a video signal input from the set unit to extract a section provided with a current for lighting pixels of the display panel and outputting a control signal; (FCCM) method in a period in which a pixel of the display panel is to be turned on according to a control signal of the timing controller, and automatically switched to a forced pulse skip mode (FPSM) And a power control integrated circuit for controlling operation of the power control IC.

In the OLED display according to the present invention, the power control integrated circuit checks whether the voltage supplied to the display panel unit is equal to or less than a preset threshold voltage, and supplies the voltage to the display panel unit when the predetermined time elapses It is desirable to shut off the power supply.

A method of driving an organic light emitting display according to the present invention includes: receiving a control signal from a timing controller; Determining whether the signal is a global shutter-off signal; Controlling to drive in the FCCM (Forced Continuous Conduction Mode) mode if the global shutter-off signal is not present, and to drive in the FPSM (Forced Pulse Skip Mode) mode in the case of the global shutter-off signal; Determining whether an output voltage supplied to the display unit is equal to or lower than a threshold voltage; determining whether a state in which the output voltage is lower than a threshold voltage continues for a threshold time or longer; And disconnecting the power supplied to the display panel unit when the output voltage is maintained below the threshold voltage for a predetermined time or more.

The threshold voltage in the present invention is preferably set to be 90% or less of the normal output voltage.

The power control integrated circuit according to the present invention, the organic light emitting display using the same, and the driving method thereof are as follows.

First, it can reduce the power consumption while maintaining the quality of the display image quality.

Secondly, it is possible to prevent the display panel from being damaged due to an error in the power control integrated circuit.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing the operation modes of a general power control integrated circuit. FIG.
FIG. 2A is a schematic view illustrating an organic light emitting display according to an exemplary embodiment of the present invention. Referring to FIG.
FIG. 2B is an exemplary view showing a schematic configuration of an OLED display according to another embodiment of the present invention. Referring to FIG.
3 is an exemplary diagram schematically showing a configuration of a PMIC according to the present invention.
4 is a diagram illustrating an operation mode of the PMIC according to the present invention.
FIG. 5 is a circuit diagram showing a detailed configuration of a PMIC in the organic light emitting display according to the present invention.
6 is an exemplary view showing a state in which an error has occurred in the switch circuit of the PMIC.
7A and 7B are diagrams illustrating an operation state when an error occurs in the PMIC according to the present invention.
8 is a flowchart illustrating a method of driving an OLED display according to an embodiment of the present invention.

For specific embodiments of the invention disclosed herein, specific structural and functional descriptions are set forth for the purpose of describing an embodiment of the invention only, and it is to be understood that the embodiments of the invention may be embodied in various forms, And should not be construed as limited to the embodiments described.

The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises ", or" having ", and the like, are intended to specify the presence of stated features, integers, But do not preclude the presence or addition of steps, operations, elements, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be construed to indicate meaning consistent with the meaning of the context in the relevant art and are to be construed as either ideal or overly formal in meaning unless expressly defined in the present application Do not.

On the other hand, if an embodiment is otherwise feasible, the functions or operations specified in a particular block may occur differently than the order specified in the flowchart. For example, two consecutive blocks may actually be performed at substantially the same time, and depending on the associated function or operation, the blocks may be performed backwards.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 2A is a schematic view illustrating an organic light emitting display according to an exemplary embodiment of the present invention. Referring to FIG. A timing controller 300 for providing an operation decision signal of the PMIC 100 and a display controller 300 for controlling the display panel 200 to display the operation panel of the display module 210, (1).

The display panel unit 200 includes a display panel 210, a gate driver 210, and a data driver 230.

The timing controller 300 analyzes a video signal input from the set unit and extracts an interval in which a current for lighting the pixels of the display panel is provided to output a power control signal (global shutter signal).

The PMIC 100 operates in a Forced Continuous Conduction Mode (FCCM) mode in which a pixel of a display panel is to be turned on in accordance with a control signal input through a control signal input terminal. In a period in which pixels are not lit, a Forced Pulse Skip Mode). Pulse Skip Mode (PSM) is to prevent current loss and increase efficiency. Pulse skipping is an operation that skips the PWM switching cycle in accordance with the excess or shortage of power supplied to the load. Pulse skipping prevents unnecessary power transfer, which can degrade the efficiency of the buck converter. When the pulse is skipped, the power control integrated circuit can discharge to the load for a longer time, more energy is delivered to the load and the output voltage is maintained. Therefore, the power consumed by the switching operation in the power control integrated circuit performing the switching regulator function is reduced, so that the power efficiency can be improved.

FIG. 2B is an exemplary view showing a schematic configuration of an OLED display according to another embodiment of the present invention. Referring to FIG. Unlike FIG. 2A, the embodiment of FIG. 2B shows an example in which the timing controller 300 and the PMIC 100 are configured in the set unit 2. FIG. The configuration is arranged in the set portion 2, but the operation is the same as that in the display module portion 1.

3 is a schematic diagram showing a configuration of a power management integrated circuit (PMIC) 100 according to the present invention. A driving voltage output terminal 120 and an input unit 110 for outputting a voltage necessary for the operation of the organic light emitting diode included in the panel of the display panel unit are connected to the input unit 110, And a power control unit 130 for controlling the driving voltage output terminal 120 according to the control signal received through the output terminal and the output voltage state of the driving voltage output terminal.

The input unit 110 includes an integrated circuit driving power input terminal VIN for receiving driving power, an operation signal input EN for receiving an operation enable signal, a control signal for receiving a control signal provided from the timing controller, And an input terminal (CIN). The control signal provided from the timing controller 300 includes a global shutter signal.

A plurality of voltages required for driving the display device are output including the high potential voltage VDDEL and the low potential voltage VSSEL through the driving voltage output terminal 120. [ The voltage according to the present invention represents only the voltage for operating the organic light emitting element.

The power control unit 130 controls the voltage required for the operation of the display panel unit according to various input signals provided through the input unit 110. At this time, the magnitude of the voltages (VDDEL, VSSEL) output through the driving voltage output stage 120 is checked to control the driving voltage output stage 120.

The structure of the internal circuit and the operation thereof will be described below.

4 is a diagram illustrating an operation mode of the PMIC according to the present invention. As shown in the figure, the PMIC according to the present invention operates in the FCCM (Forced Continuous Conduction Mode) mode during the time t _ON that the pixels of the display panel are to be turned on according to the global shutter signal provided from the timing controller, (Forward pulse skip mode) during the time t _OFF during which the light emitting diode OL is not turned on. Therefore, the FCCM type operation with a relatively high power consumption rate is performed only while the pixels of the display panel are turned on, while the global voltage is not changed by providing the output voltage constantly, So that the power consumption can be reduced.

FIG. 5 is a circuit diagram showing a detailed configuration of a PMIC in the organic light emitting display according to the present invention. The PMIC 100 includes an input unit 110 receiving a plurality of input signals from the outside, a driving voltage output terminal 120 and an input unit 110 for outputting a voltage required for operation of the organic light emitting diode included in the panel of the display panel unit And a power control unit 130 for controlling the driving voltage output terminal 120 according to the control signal received through the output terminal and the output voltage state of the driving voltage output terminal.

The input unit 110 includes a terminal VDD for transmitting an operation voltage, a V-OFF terminal V-OFF, a ground power terminal GND, and an operation signal input EN for receiving a drive start enable signal, , And a control signal input terminal (CIN) receiving a global shutter signal provided from the timing controller.

The driving voltage output terminal 120 is constituted by a switching circuit that performs switching operation by a switching control signal provided from the power supply control unit 130. [ The voltage to be transmitted to the display panel 210 varies depending on the connection state of the switch circuit. The operation of the switch circuit may be implemented by a device such as a MUX.

The switch circuit includes a pair of driving voltage switches SWD1 and SWD2 connected to the VDD voltage input terminal of the display panel 210; And a pair of discharge voltage switches SWS1 and SWS2 connected to a VSS voltage input terminal of the display panel 210. [

Various input signals provided through the input unit 110 are transmitted to the power control unit 130. The power control unit 130 controls the operation of the switch circuit included in the driving voltage output stage 120 by checking the magnitude of the voltages VDDEL and VSSEL provided to the display panel unit through the driving voltage output stage 120.

The timing controller extracts a section provided with a current for lighting the pixels of the display panel and outputs a power control signal (global shutter signal).

Meanwhile, in the present invention, the operation of automatically switching from the FCCM mode to the FPSM mode may be implemented by a control signal output from the timing controller 300. [ That is, the timing controller 300 analyzes the video signal input from the set unit and controls the conversion operation mode of the converter incorporated in the PMIC 100. [

When driven in the PSM (Pulse Skipped Mode) scheme, the drive pulse DPS is omitted at least once. On the other hand, if the driving pulse DPS is continuously output continuously, the power control integrated circuit operates in the CCM (Continuous Conduction Mode) mode. That is, in the present invention, the timing controller analyzes the image signal and senses the magnitude of the current consumed. Thereby controlling the consumption current supplied to the display panel through the power control integrated circuit. That is, when the magnitude of the consumption current is smaller than or equal to the reference value, the driving is performed by the PSM method in which the driving pulse of one period is omitted. On the other hand, when the magnitude of the current consumption is larger than the reference value, it is driven by the CCM method. On the other hand, the duty ratio of the driving pulse when the PSM system is different from the duty ratio of the driving pulse when the CCM system is the DCM system. For example, the duty ratio of the drive pulse when the PSM method is set to be larger or smaller than the duty ratio of the drive pulse when the CCM method is used.

6 is an exemplary view showing a switch state when an error occurs in a drive voltage output terminal. The power control unit 130 outputs a switching off signal to the switch circuits SWD1 and SWS1 of the drive voltage output stage 120 according to the global shutter off signal provided from the timing controller. If the switch circuits SWD1 and SWS1 are short-circuited due to an internal factor or an external factor, it may occur. At this time, when both the switches SWD1 and SWS1 are short-circuited, the VDD power is continuously transmitted to the VDDEL terminal of the display panel 210, and the ground power is continuously transmitted to the VSSEL terminal. The power control unit 130 of the power control integrated circuit 100 can continuously check the current supplied to the display panel unit through the driving voltage output terminal 120 to grasp the states of the switch circuits SWD1 and SWS1.

In this abnormal state, the organic light emitting diode is continuously supplied with the operating voltage, and the operation current I _OLED is continuously transmitted to maintain the light emitting operation state. The luminance at the time of the abnormal operation rises by about five times the luminance of the normal driving state, which may cause a fatal problem.

7A and 7B are diagrams illustrating an operation state when an error occurs in the PMIC according to the present invention. Two types of embodiments are shown. That is, the first threshold voltage V _th1 and the second threshold voltage V _th2 can be set in comparing the output voltage output through the driving voltage output terminal with the threshold voltage V _th . voltage (V _th1) can be set to a second threshold voltage (V _th2) larger than, the threshold time (dt _th) is the first threshold time (dt ₁₎ and the second threshold time (dt _2). These embodiments are intended to illustrate the invention and are not to be construed as limiting the invention.

When the global shutter-off signal is provided from the timing controller, the PMIC 100 is automatically switched to the PSM mode. Accordingly, the power control unit 130 supplies the driving current amount provided to the display panel unit 210 through the driving voltage output terminal 120 at a low level. The power control unit 130 continuously monitors the output voltage of the driving voltage output terminal 120 according to the present invention. Even when an error occurs in the switch circuit, the current continues to flow to the display panel portion. When the PSM mode is forcibly switched according to a signal provided from the timing controller, the output voltage output through the driving voltage output terminal 120 is lowered.

The power control unit 130 checks the output voltage of the driving voltage output terminal 120 and determines that an error has occurred in the switch circuit when a low voltage is continuously output. If the error state of the switch circuit is not temporary, the output voltage is kept low and reaches the first threshold voltage V _th1 . The first threshold voltage V _th1 can be set to about 90% of the normal output voltage. At this time, the first threshold time dt ₁ may be set to a time that is relatively longer than the second threshold time dt ₂ . The threshold voltage or the threshold time is a value that can be changed by the designer of the power control integrated circuit in accordance with the actual application environment or the requirements of the customer and is for example described in the description of the invention and the present invention is not limited thereto .

When the output voltage is equal to the threshold voltage (V _th1) or lowered condition persists for a critical period of time (dt _1), the power control unit 130 is insulated from the power source provided as part the display panel.

7B shows a case where the threshold voltage V _th is set to the second threshold voltage V _th2 . That is, the voltage is equal to or lower than the first threshold voltage V _{th1 when the} voltage is set to about 90% of the normal output voltage. For example, it can be set to about 80% of the normal output voltage, which will not be discussed in accordance with the application of the present invention. At this time, the second threshold time dt ₂ should be set to a time shorter than the first threshold time dt ₁ .

When the output voltage is equal to the threshold voltage (V _th2) or lowered state the second threshold time (dt ₂₎ over time, the power control unit 130 is insulated from the power source provided as part the display panel.

8 is a flowchart illustrating a method of driving an OLED display according to an embodiment of the present invention. Since the method of driving the organic light emitting display according to the present invention operates substantially as FCCM or FPSM according to the global shutter signal provided from the timing controller, the following process will be described with the focus on the operation of the power control unit in the PMIC.

Upon receipt of the control signal including the global shutter signal from the timing controller (step S801), a signal for controlling the switch circuit of the drive voltage output stage is output in accordance with the global shutter signal (step S802).

If it is not the global shutter-off signal, control is made to drive in the FCCM (step S803), and in the case of the global shutter-off signal, control is made to drive in the FPSM (forced pulse skip mode) .

At this time, the output voltage of the driving voltage output terminal is monitored and compared with the threshold voltage (V _th ). That is, it is checked whether there is an abnormality in the switch circuit. If no abnormality occurs, control returns to the process of receiving the control signal (step S805).

When the output voltage becomes equal to or lower than the threshold voltage V _th , the state holding time dt is compared with the threshold time dt _th . The case where the abnormal operation state is temporary is considered (step S806).

If the state in which the output voltage is equal to or lower than the threshold voltage V _th is continuously maintained for the threshold time dt _th or more, the circuit performs SCP (Short Circuit Protection) or UVP (Under Voltage Protection). That is, when the voltage provided to the display panel unit becomes lower than a predetermined voltage, the power supply to the display panel unit is shut down. When a short-circuit occurs, the output voltage is immediately turned off, thereby protecting circuits and devices including the display panel unit from the risk of fire due to an overcurrent when an abnormal short occurs (step S807).

As described above, the power control integrated circuit according to the present invention operates in the FCCM (Forced Continuous Conduction Mode) method in a period in which pixels of the display panel are to be turned on, and in a Forced Pulse Skip Mode ) Method, power consumption by the power supply circuit can be reduced while maintaining the image quality of the portable display device.

In addition, it is checked whether the voltage supplied to the display panel unit is equal to or smaller than a preset threshold voltage through the driving voltage output terminal. When the predetermined time elapses, the power supply to the display panel unit is cut off, It is possible to prevent the display panel from being damaged due to an internal error.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

1: Display module part 2: Set part
100: PMIC 110: Input
120: driving voltage output terminal 130: power supply control section
200: display panel unit 210: display panel
220: gate driver 230: data driver
300: timing controller

Claims (6)

An integrated circuit driving power input terminal for receiving driving power;
An operation signal input terminal for receiving a drive start enable signal;
A driving voltage output terminal for outputting a voltage required for operation of the organic light emitting diode provided in the panel of the display panel unit;
A control signal input terminal receiving a control signal provided from a timing controller; And
According to a control signal input through the control signal input terminal, a FCCM (Forced Continuous Conduction Mode) method is used in a period in which pixels of a display panel are to be turned on, while a Forced Pulse Skip Mode (FPSM) And a power control section for controlling the drive voltage output terminal to operate. The plasma display apparatus according to claim 1,
A pair of driving voltage switches SWD1 and SWD2 connected to the VDD voltage input terminal of the display panel unit;
And a pair of discharge voltage switches (SWS1, SWS2) connected to the VSS voltage input terminal of the display panel section. The power supply controller according to claim 1, wherein the power control unit checks whether the voltage supplied to the display panel unit is equal to or less than a predetermined threshold voltage through a driving voltage output terminal, and supplies the voltage to the display panel unit And the power supply is cut off. A display panel unit including a display panel, a gate driver, and a data driver;
A timing controller for analyzing a video signal input from the set unit to extract a section provided with a current for lighting pixels of the display panel and outputting a control signal;
The controller operates in the FCCM (Forced Continuous Conduction Mode) mode in a period in which pixels of the display panel are to be turned on in accordance with the control signal of the timing controller, and controls to operate in a FPSM (Forced Pulse Skip Mode) And a power control integrated circuit. 5. The integrated circuit of claim 4, wherein the power control integrated circuit comprises:
Wherein the control unit checks whether the voltage supplied to the display panel unit is equal to or less than a predetermined threshold voltage and cuts off power supplied to the display panel unit when the predetermined time or more elapses. Receiving a control signal from a timing controller;
Determining whether the signal is a global shutter-off signal;
Controlling to drive in the FCCM (Forced Continuous Conduction Mode) mode if the global shutter-off signal is not present, and to drive in the FPSM (Forced Pulse Skip Mode) mode in the case of the global shutter-off signal;
Determining whether an output voltage supplied to the display unit is equal to or smaller than a threshold voltage;
Determining whether a state where an output voltage is equal to or less than a threshold voltage continues for a threshold time or longer;
And disconnecting the power supplied to the display panel unit when the output voltage is equal to or lower than the threshold voltage for a predetermined period of time or longer.

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